The known exchangeable frames for transparencies consist, in general, of a top part and a separate bottom part which have to be joined together, by manual work, either by the manufacturer or by the ultimate user.
The invention has set itself the task to develop an exchangeable frame mentioned at the beginning in such a manner that a joining-together of the top part and the bottom part is substantially facilitated and can, if desired, be effected automatically.
In accordance with the invention, this is achieved in that (the) top part and bottom part aare manufactured, more especially injection-moulded, from one piece and that (the) top part and bottom part are connected by one or several elements which facilitate the joining-together of the hinge.
It is particularly advantageous to design the elements as connecting plates which, after the folding-over of the top part towards the bottom part, snap into the bottom part and support the hinge locally.
Through the connection of the top part to the bottom part via the connecting plates, the relative movement between the two parts is narrowly confined to a swinging movement which, perforce, joins the hinges of the exchangeable frame together. The exchangeable frame in accordance with the invention can thus be joined together extremely rapidly and even automatically in a simple manner.